Question: Simplify the following expression: $n = \dfrac{a}{8} - \dfrac{10a}{3}$
Solution: In order to subtract expressions, they must have a common denominator. The smallest common denominator is the least common multiple of $8$ and $3$ $\lcm(8, 3) = 24$ $ n = \dfrac{3}{3} \cdot \dfrac{a}{8} - \dfrac{8}{8} \cdot \dfrac{10a}{3} $ $n = \dfrac{3a}{24} - \dfrac{80a}{24}$ $n = \dfrac{3a -80a}{24}$ $n = \dfrac{-77a}{24}$